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By Sara Hart

SM&W took acoustic site measurements and determined that the biggest problem was the loud, low-frequency train noise. To mitigate this, SM&W designed special windows, consisting of two layers of 1¼2-inch glass in an aluminum frame with a 5-inch airspace separating the two layers. Special gaskets seal out the noise. In this case, the fresh air intakes were located on the roof rather than in the window assemblies. The levels on the facade exposed to the helicopter route were actually less intrusive. Here, the window assemblies were designed with a smaller 21¼4-inch airspace.

 

One Raffles Quay in Singapore by Kohn Pedersen Fox Architects consists of high-rises that share a plinth with a district cooling system in between. The 20 cooling towers in the plant meant that propeller fan blades would be located within 4 feet of the towers’ curtain walls. Besides finding a manufacturer of “super quiet” cooling towers, the engineers recommended a laminated curtain wall to reduce the low-frequency rumble of the towers. The chart shows the results of the tower noise review. Rendering: Courtesy Kohn Pedersen Fox

The Mandarin Oriental and 85 Adams have similar noise sources and, therefore, share similar but not identical solutions. While both projects have traffic noise, 85 Adams adds subway commotion to the total, and the Mandarin has persistent helicopter traffic. But the consistent subway noise at 85 Adams trumps the less frequent occurrence of helicopters at the Mandarin, requiring a deeper window assembly.

SM&W also works to mitigate environmental noise for a lot of other projects, such as a 58-story mixed-use development on Mission Street in San Francisco, designed by Handel Architects, which is adjacent to the East Bay Transit Bus Terminal. (California Building Code requires environmental noise mitigation in residences and other facilities where there are sleeping rooms.) Meanwhile, for One Raffles Quay, an office complex in Singapore designed by Kohn Pedersen Fox, the SM&W engineers created a model of noise transmission levels of proposed cooling towers by actually measuring similar towers in other locations.